Air-circulation system for ovens



.I lme 24, 1930. y, A, FOX

AIR CIRCULATION SYSTEM FOR ovENs Filed June 22, 1928 @che mv@ Q@ @6 mv@ nu es e@ s@ e@ es e@ seh@ sa es es sa a o.

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airboy/mm3 Patented -June 24, 1930 UNITED STATE/s PATENT OFFICE `V'EIR'NIE FOX, 0F DETROIT, MICHIGAN, ASSIGNOR TO YOUNG BROTHERS COMPANY,

F DETROIT, MICHIGAN, A CORFORATION 0F MICHIGAN Ain-CIRCULATION SYSTEM Eon ovENs I Applicationled June 22,

The present invention pertains to a novel oven of the typev in which 'a conveyor carries a number of metal plates which have been enameled, painted, japanned or otherwise treated and which require drying.

In the particular oven constituting the subject matter of the invention, a stream of air is caused to circulate in the direction opposite to that of the conveyor. It is the object of the invention to ei'ect the circulation of air in such a manner that the entering plates are first heated by the exhausting air, then passed through the hotter zone of the oven, and finally through a cooling zone prior to being taken out of the oven. This arrangement utilizes the heat in the air to a satisfactory degree and permits the dried plates to be discharged from the oven in a condition suitable' for handling.

The invention is fully disclosed by way of example in the following description and in the accompanying drawing, in which- Figure 1 is a vertical section of anV oven constructed according to the invention;

Fig. 2 is a vertical section at right angles to Figure 1; and Y Fig. 3 is a detail section in a plane parallel to that of Figure 1, showing the construction of the conveyor.

Reference to these views will now be made by use of like characters which are employed to designate corresponding parts throughout.

The body of the oven consists of a vertical and hollow column 1 having a loading opening 2 in one wall thereof, at the bottom, and an unloading opening 3 in the opposite wall and also at the bottom. In the top of the oven is journalled a shaft -4 carrying an exterior gear 5 by meansof which it is driven. Within the oven, the shaft carries a pair of sprocket wheels 6 close to the side walls. At the base of the oven, and exteriorly thereof, are provided a pair of upright bearings 7 contiguous to opposite walls and aligned to support a shaft 8 parallel to the shaft 4. The bearing holes 9 are elongated in the vertical direction, and so are the slots 10 in the side walls through 50 which the shaft passes, so that the distance 192s. serial No. 287,523. i

between the shafts 4 and 8 is permitted to vary as pointed out more in detail below. The 'shaft 8 carries a pair of sprocket wheels 11 in line with the wheelsy on `the shaft 4. Each pair of aligned sprocket wheels /is trained by a sprocket chain 12.

Each chain consists of double links 13 connected by pins 14 in the usual manner. Certain of these pins at intervals are slightly extended inwardly of the oven as indicated by the numeral 15 in Figure 2. Fingers 16 are suspended from the extensionsby means o f integral bosses 17 receiving such extensions. Each pair of opposed fingers 16 suports a stirrup or cradle 18 depending thererom and attached thereto by rivets 19. The stlrrup is completed by transverse bars 20 secured to the base portion thereof as shown more clearly in Figure 3. The coated plates to be dried are entered into the oven through the opening 2 and erected upon the bars 20 which maintain a horizontal position throughout the entire course of the endless conveyor. The shaft 4 is driven in a manner to turn the wheels 6 and 11 in the clockwise direction as viewed in Figure 1, so that the ascending side of the conveyor rises from the work inlet 2 and the other side descends towards the work outlet 3. The latter opening is also used for admission of air into the oven.

A heating element 21 of any desired or suitable character is mountedin the oven slightly above the shaft 8. Above the work inlet 2, the oven wall is formed with an air exhaust p ort 22 connected to a suction fan 23 by a plpe 24. In order to prevent withdrawal of hot air directly from the heating element through the port 22 without reachlng. the upper part of the oven, a baiie plate 90 25 1s arranged between the heating element and the ascending side of the conveyon/ This member extends to substantially the top of the oven and is bent under the heating element as indicated by the numeral 26'. 95 The baiie system is completed by a guard 27 extending from a point opposite the air intake 3 to a point somewhat/above the top o f the heating element. The guard is positioned between the heating element and 100 the descending side of the conveyor Aand contacts with the portion 26 in order -to obstruct a-direct path from the heating ele"-y ment to the port 22. The disposition ofthe lower part ofy the guard op `osite the lair intake 3 reduces the flow pat `between the air intake ,and the port 22, although the.

edges'of this lower portion of the guard are cutout at 28 toy accommodate thewheels 11. Both plates and 27 have their edges supported in o posite walls of the body 1. The action o the suction fan 23 vproduces a' current of fresh air .entering the ovenl through the intake 3. This -air is substantially cool while rising along the guard 27 and is heated after passing the top f the guard. The fan causes this stream to travel over the top of the baile 25 and down to the exhaust port 22. K

The work which is admitted through. the opening 2 rises through this descending stream of hot air and is in this way preheated before coming to the hotter zones at the opposite side of the bale 25. After having passed the upper edge of the guard 27 on the descending side of the conveyor, the

l work has been suiiiciently heated and now enters they cooler zone directly ad'acent the guard 27. Consequently the wor is Withdrawn through the opening 3 in a cooled condition which facilitates handling and dispenses with supplementary cooling equipment. Y

Although a specific embodiment` of the invention has been illustrated and described,-

it will beunderstood that various alterations in the details of construction may be made without departing from the scope of the invention as indicated by the appended claims. 40

1. In an oven, a vertically moving conveyor, a Work inlet and a work outlet at the bottom of the oven and at the ascending and descending sides respectively of the conveymeans and extending beneath said heat source into engagement with saidguard.

3. lIn an oven, a vertically moving conveyor, work inlet and air 'exhaust means in the bottom of s'aid oven atthe ascending side ofl said conveyor, work outlet and alir` inlet means at the descending side o f said conveyor, a heat source in said oven, a baie partitioningthe heat exchange area of said sourceV from 'said exhaust means, and a ard partitioning the heat exchan e area o said exchange area and air exhaust'meansA andv extending beneath said heat source into engagement with said guard. A

In testimony whereof Iafix my 'signature.

' VERNIE A. FOX.

or, air inlet means at the work outlet and air exhaust means at the opposite wall of the oven, a heat source in said oven, abaiile partitioning the heat exchange area of said source from said'exhaust means, and a partitioning the heat exchange area. o said heat sorce from the descending side of the conveyor to provide a cooling zone at said work outlet.

2. In an oven, a vertically moving conveyor, a work inlet and a work outlet at the ard l b'ottom of the oven and at the ascending i and descending sides respectively of the con-V veyor, air inlet means at the work outlet and air exhaust means at the opposite Wall of the oven, a heatsource in said oven, a

guard partitioning the heat exchangesarea# of said heat sourcefrom the descending side of the conveyor to provide a cooling zone at said work outlet, and a bale between said heat exchange area and air exhaust 

